Plasma PC Research Articles

Laboratory testing issues for protein C, protein S, and antithrombin.

Thrombophilia is a complex disease process, which clinically expresses as venous thrombosis. The presence of a genetic defect in one of the major contributing components (protein C [PC], protein S [PS], and antithrombin [AT]) to thrombophilia can be determined by clinical laboratory assays. However, understanding the limitations and problems associated with assays is paramount to an accurate analysis of the genetic status. This review will discuss the major analytical issues and provide recommendations for assaying PC, PS, and AT in plasma. Recommendations are also made about pre-analytical and postanalytical issues clinically affecting these assays.

Trimethoprim–Sulfamethoxazole Treatment Does Not Reverse Obstructive Pulmonary Changes in Pneumocystis-Colonized Nonhuman Primates With SHIV Infection

Despite antiretroviral therapy and trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis, Pneumocystis pneumonia remains an important serious opportunistic infection in HIV-infected persons. Pneumocystis (Pc) colonization in HIV-infected individuals and in HIV-uninfected smokers is associated with chronic obstructive pulmonary disease (COPD). We previously developed a nonhuman primate model of HIV infection and Pc colonization and demonstrated that Pc colonization correlated with COPD development. In the present study, we examined kinetics of COPD development in non-human primate and tested the effect of Pc burden reduction on pulmonary function by TMP-SMX treatment. Cynomolgus macaques (n = 16) were infected with simian/human immunodeficiency virus (SHIV89.6P), and natural Pc colonization was examined by nested polymerase chain reaction of serial bronchoalveolar lavage fluid and anti-Pc serology. Eleven of 16 monkeys became Pc colonized by 16 weeks post simian-human immunodeficiency virus (SHIV) infection. Pc colonization of SHIV-infected monkeys led to progressive declines in pulmonary function as early as 4 weeks after Pc detection. SHIV-infected and Pc-negative monkeys maintained normal lung function. At 25 weeks post-SHIV infection, TMP-SMX treatment was initiated in 7 Pc-positive (Pc+) (TMP: 20 mg/kg and SMX: 100 mg/kg, daily for 48 weeks) and 5 Pc-negative (Pc-) monkeys. Four SHIV+/Pc+ remained untreated for the duration of the experiment. Detection frequency of Pc in serial bronchoalveolar lavage fluid (P < 0.001), as well as plasma Pc antibody titers (P = 0.02) were significantly reduced in TMP-SMX-treated macaques compared with untreated. Reduction of Pc colonization by TMP-SMX treatment did not improve pulmonary function, supporting the concept that Pc colonization results in early, permanent obstructive changes in the lungs of immunosuppressed macaques.

Plasma D-dimer as a Prognostic Marker in ICU Admitted Egyptian Children with Traumatic Brain Injury.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in children. This study aimed at evaluation of the D-dimer blood levels as a new marker to predict prognosis and outcome of traumatic brain injuries among children. This case control study was conducted at the Paediatric Intensive Care Unit (ICU), Alharm Hospital in Giza, Egypt during 2012-2013, on 46 Paediatric cases admitted to ICU with head injury and 20 normal age-matched controls. Clinical data and venous blood samples were prospectively collected at 1(st), 3(rd) and 14(th) day of admission, in addition to examination finding as Glasgow coma scale (GCS), cranial brain computed tomography (CT), routine laboratory investigations (CBC, CRP, SGOT, SGPT, urea, creatinine, random blood glucose, Na, K and arterial blood gases) plasma D-dimer, INR, PT, aPTT and PC. Data analysis was carried out accordingly and ROC curve was performed to explore the discriminating ability of D-dimer through estimation of its accuracy in differentiating temporal survivorship of those with TBI. Cases were classified according to outcome into survivors and non-survivors. Significant difference was observed between cases and controls and between survivors and non-survivors during 1(st), 3(rd) and 14(th) day of the follow up including GCS, blood levels of D-dimer, PT and aPTT. ROC curve analysis for D-dimer showed decline in both sensitivity from 89.5% to 73.7% and specificity from 100% to 81.5% along the study days respectively. D-dimer time measurements showed significant decline among survivors from 4.2 to 0.7, while in the non survivor group this decline was much higher from 27.9 to 1.4. Low plasma D-dimer suggests the absence of brain injury, and good prognosis.

Registry Of Patients Treated With Protein C Concentrate (Human) In The United States and Europe: Interim Results

BackgroundProtein C (PC) is a naturally occurring, vitamin-K dependent anticoagulant produced by the liver. Deficiency of PC, which can be congenital or acquired, results in a hypercoagulable state. Patients with severe PC deficiency may manifest severe, often life-threatening, disseminated intravascular coagulation (DIC), purpura fulminans (PF), and/or thromboembolism. Highly purified protein C concentrate prepared from human donor plasma (Ceprotin; Baxter Healthcare Corporation, Westlake Village, CA) is an approved therapy for prevention and treatment of venous thrombosis and PF in patients with severe congenital PC deficiency (SCPCD) in the United States. It is indicated in patients with SCPCD for PF and coumarin-induced skin necrosis, and short-term prophylaxis in the European Union and other countries. Use of protein C concentrate (human) has been reported in patients with acquired PC deficiency. The Ceprotin Treatment Registry is a prospective, international, multi-center, open-label, non-interventional, observational study designed to examine the long-term safety and effectiveness of protein C concentrate (human) in the clinical setting. This is the first large, real-world assessment of the treatment of a rare disease with protein C concentrate (human). Here we report data from the first interim analysis in June 2013 covering a 3-year enrollment period. MethodsPatients of any age who received, or were initiating/receiving protein C concentrate are included. The study duration is 5 years (3-year enrollment period plus 2 years of follow-up). All study visits/assessments are in accordance with standard of care, with protein C concentrate dose, dose frequency, duration and route of administration determined by the investigator. The study objectives are to determine the most common medical diagnoses associated with protein C concentrate treatment, protein C concentrate treatment regimens, and safety information based on all serious adverse events (SAEs) and rate of treatment-related AE. Other objectives include: an examination of the relationship between protein C concentrate treatment and outcomes in all registry participants, as well as various subgroups. Descriptive statistical analyses are used. ResultsAt the time of data extraction, 34 patients were enrolled from 26 centers; 10 centers in the United States and 16 centers in Europe. Half of the patients were males. The primary diagnosis of PC deficiency was congenital in 25 patients (73.5%) and acquired in 9 patients (26.5%). The median age at diagnosis was 0.03 years (range 0–19.9). Mean plasma PC activity level was 9% (range 1–40.0). The most common (in ≥3 patients) thrombotic disease-associated conditions were PF (50.0%); blindness (44.1%); thromboembolic disease (41.2%), which included deep vein thrombosis, arterial thrombosis and DIC; stroke (32.4%), and renal dysfunction (8.8%). Of the 23 patients being treated with protein C concentrate, 15 were administered protein C concentrate intravenously, and 8 patients received protein C concentrate subcutaneously. The body weights of patients receiving subcutaneous treatment ranged from 10.0 kg to 57.9 kg. A total of 15 patients received an anticoagulant treatment in addition to protein C concentrate. Eight patients reported 23 SAEs, all of which were considered not related to treatment. Eighteen (52.9%) patients reported 72 AEs; only 1 of them, an episode of upper respiratory infection, was considered possibly treatment-related. In 18 patients in whom PC activity recovery was determined after protein C concentrate treatment, there were no patients documented with poor recovery. Protein C concentrate was used during 18 surgeries/invasive procedures and considered effective in all interventions for which data were available. ConclusionsData from the first interim analysis of the Ceprotin Treatment Registry demonstrate that patients with both congenital and acquired severe PC deficiency who are treated with protein C concentrate (human) have a low incidence of treatment related SAEs and AEs, and treatment with protein C concentrate appears to be effective when used during surgery/invasive procedures. Further patient follow up will shed light onto clinical treatment outcomes. Disclosures:Manco-Johnson:CSL Behring: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Biogen Idec: Membership on an entity's Board of Directors or advisory committees; Baxter BioScience: Membership on an entity's Board of Directors or advisory committees; Bayer HealthCare: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Research Funding. Knoebl:Novo Nordisk: Consultancy, Honoraria; Baxter: Consultancy, Honoraria. Shapiro:Cangene: Research Funding; Biogen Idec: Research Funding; Baxter BioScience: Research Funding; Bayer HealthCare: Research Funding. Finnerty:Baxter: Employment, Equity Ownership. Yel:Baxter: Employment, Equity Ownership. Gelmont:Baxter: Employment, Equity Ownership.

Antibody SPC-54 provides acute in vivo blockage of the murine protein C system

Multiple protective effects of pharmacological activated protein C (APC) are reported in several organ pathologies. To help evaluate the endogenous murine PC system, we characterized a rat monoclonal anti-mouse PC antibody, SPC-54, which inhibited the amidolytic and anticoagulant activities of murine APC by>95%. SPC-54 blocked active site titration of purified APC using the active site titrant, biotinylated FPR-chloromethylketone, showing that SPC-54 blocks access to APC's active site to inhibit all enzymatic activity. A single injection of SPC-54 (10mg/kg) neutralized circulating PC in mice for at least 7days, and immunoblotting and immuno-precipitation with protein G-agarose confirmed that SPC-54 in vivo was bound to PC in plasma. Pre-infusion of SPC-54 in tissue factor-induced murine acute thromboembolism experiments caused a major decrease in mean survival time compared to controls (7min vs. 42.5min, P=0.0016). SPC-54 decreased lung perfusion in this model by 54% when monitored by vascular perfusion methodologies using infrared fluorescence of Evans blue dye. In LD50 endotoxemia murine models, SPC-54 infused at 7hr after endotoxin administration increased mortality from 42% to 100% (P<0.001). In summary, monoclonal antibody SPC-54 ablates in vitro and in vivo APC protective functions and enzymatic activity. The ability of SPC-54 to block the endogenous PC/APC system provides a powerful tool to understand better the role of the endogenous PC system in murine injury models and in cell bioassays and also to neutralize the enzymatic activities of murine APC in any assay system.

Mystery of idiopathic male infertility: is oxidative stress an actual risk?

To study the role of oxidative stress in sperm dysfunction in Turkish idiopathic infertile men. Prospective study. Medical laboratory. Semen samples from 28 idiopathic infertile men and 14 fertile men. Sperm DNA fragmentation and reactive oxygen species (ROS) formation were assayed with the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) test and 2',7'-dichlorodihydrofluorescein, respectively. Seminal plasma protein carbonyl groups (PC), nitrotyrosine (NT), malondialdehyde (MDA), and total thiol (SH) levels and ferric reducing antioxidant power (FRAP) were determined. Sperm DNA fragmentation in relation to ROS formation and seminal plasma oxidative parameters. The number of TUNEL-positive spermatozoa from idiopathic infertile men was higher than from fertile men, and ROS formation was increased as well in infertile males. A positive correlation was detected between TUNEL-positive cells and ROS content. Seminal plasma MDA, PC, and NT levels were elevated in idiopathic infertile males. No difference was observed in the total SH content and FRAP. Seminal plasma MDA levels correlated positively with both NT and PC levels. Positive correlations were detected between DNA fragmentation and MDA, NT, and PC of seminal plasma, and between sperm ROS content and MDA levels. The results of this study support the presence of oxidative stress in sperm dysfunction in Turkish idiopathic infertile men.

A unified algorithm for predicting partition coefficients for PBPK modeling of drugs and environmental chemicals

The algorithms in the literature focusing to predict tissue:blood PC ( P tb ) for environmental chemicals and tissue:plasma PC based on total ( K p ) or unbound concentration ( K pu ) for drugs differ in their consideration of binding to hemoglobin, plasma proteins and charged phospholipids. The objective of the present study was to develop a unified algorithm such that P tb , K p and K pu for both drugs and environmental chemicals could be predicted. The development of the unified algorithm was accomplished by integrating all mechanistic algorithms previously published to compute the PCs. Furthermore, the algorithm was structured in such a way as to facilitate predictions of the distribution of organic compounds at the macro (i.e. whole tissue) and micro (i.e. cells and fluids) levels. The resulting unified algorithm was applied to compute the rat P tb , K p or K pu of muscle (n = 174), liver (n = 139) and adipose tissue (n = 141) for acidic, neutral, zwitterionic and basic drugs as well as ketones, acetate esters, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons and ethers. The unified algorithm reproduced adequately the values predicted previously by the published algorithms for a total of 142 drugs and chemicals. The sensitivity analysis demonstrated the relative importance of the various compound properties reflective of specific mechanistic determinants relevant to prediction of PC values of drugs and environmental chemicals. Overall, the present unified algorithm uniquely facilitates the computation of macro and micro level PCs for developing organ and cellular-level PBPK models for both chemicals and drugs.

Muscle Fiber Type And Blood Oxidative Stress Following Muscle Damaging Strength Exercise

Acute participation in high intensity strength type exercise elicits a transient blood oxidative stress. Factors underlying the oxidative stress magnitude, however, are poorly understood. There is a rationale to suspect that muscle fiber type composition may influence the magnitude of the blood oxidative stress response to acute strength training. PURPOSE: To determine whether muscle fiber type correlates to the magnitude of blood oxidative stress following acute strength type exercise. METHODS: Eleven college aged males performed muscle damaging strength exercise which involved 3 sets of 50 eccentric-action repetitions at a rate of 30 degrees/second. Heparinized blood plasma samples taken Pre, Post, 24 hours, 48 hours, 72 hours, and 96 hours post muscle damaging exercise were assayed for comparison of muscle damage (creatine kinase - CK, and lactate dehydrogenase - LDH) and oxidative stress biomarkers (uric acid - UA, Ferric Reducing Antioxidant Power - FRAP, Trolox-Equivalent Antioxidant Capacity - TEAC, lipid hydroperoxides - LOOH, and protein carbonyls - PC). Muscle biopsies were taken of the vastus lateralis prior to the muscle damaging exercise protocol and subsequently assayed to determine the relative percentage of slow and fast type muscle fibers. Relationships between oxidative stress, muscle damage, and muscle fiber type were examined. RESULTS: A mixed fiber composition existed (Type I = 36.2 +/- 4.7%, Type IIa = 34.3 +/- 3.1, Type IIx = 29.53 +/- 2.73%; p = 0.366). Plasma CK levels peaked 24-96 hours post exercise (214%, p = 0.002) while LDH levels peaked between Post and 96 hours post (18%, p = 0.012). No elevation in Pre-to-immediately-Post sample oxidative stress biomarkers was observed. An elevation in plasma PC existed, however, 24, 48, 72, and 96 hours (p = 0.032) post strength exercise, with a peak response of 126% (p = 0.012) above baseline. No statistically significant correlations existed between muscle fiber composition and elevations in plasma markers for oxidative stress or muscle damage. CONCLUSIONS: A fiber type - oxidative stress relationship did not exist following muscle damaging strength type exercise. Further study is needed to determine whether a fiber type-oxidative stress relationship exists in individuals with fast or slow muscle fiber type predominance.

Solitary plasmacytoma of bone: a clinicopathologic, immunohistochemical and immunoglobulin gene rearrangement study

To investigate clinicopathologic features of solitary plasmacytoma of bone (SPB) and the role of immuno-phenotype and immunoglobulin gene rearrangement detection in the diagnosis and differential diagnosis of SPB. A total of 21 cases of SPB were selected during a period from 1990 to 2008. A retrospective clinicopathologic study and immunohistochemistry (EnVision or EliVision methods) of 17 antigens were performed. In addition, universal IgH (FR3A/LJH/VLJH) primers and BIOMED-2 PCR multiplex tubes were used for IgK and IgL rearrangement analysis. The age of patients ranged from 36 to 72 years with a media of 50 years. Axial skeleton was the most common site of involvement, accounting for 66.7% of the cases (14 of 21), followed by the extremities of 33.3% (7 cases). Low serum level of M-components was found in 5 cases, including two of IgG type (21.4 g/L) and three of IgA type. Clinical manifestations were closely related to the anatomic sites involved, such as pain due to bone destruction, symptoms and signs caused by compression of spinal cord or nerve root, and pathological fracture. All cases presented as a solitary osteolytic lesion. According to the histological grading criteria, grade I tumor was seen in 12 of 21 cases (57.1%). The remaining were grade II (5 cases, 23.8%) and grade III (4 cases, 19.0%). Immunohistochemically, the neoplastic cells expressed two or more plasma cell antigens, including CD138, CD38 and PC, but no CD19 and CD20. CD79a expression detected in 23.8%(5/21) of the cases. Expression of CD56, CD27 and CD44v6 were 57.1% (12/21), 15.0% (3/20) and 23.8% (5/21), respectively. Follow-up data were available in 12 of the 21 patients (57.1%). Five patients were alive and 7 died. Three patients developed multiple myeloma (MM) and died of the tumor. SPB is a rare tumor with bone pain as the most common presenting symptom due to bone destruction. The diagnosis of EMP can only be established after exclusion of an extramedullay invasion by MM. Immunophenotype and IgH gene rearrangement analysis play important roles in the diagnosis of SPB.

Surfactant phospholipids, surfactant proteins, and inflammatory markers during acute lung injury in children

To explore the pathophysiology of acute lung injury in children. Prospective cohort study. Regional University Hospital, pediatric intensive care unit. Children without a preexisting lung injury who developed acute lung injury and were intubated were eligible for the study. Children without lung injury and intubated for minor surgical procedures acted as controls. Bronchoalveolar lavage fluid and blood were collected on days 1 to 4, weekly, and immediately before extubation during acute lung injury. Molecular species compositions of phosphatidylcholine were determined by electrospray ionization mass spectrometry of lipid extracts of bronchoalveolar lavage fluid supernatants. Surfactant proteins A, B, and D and interleukin-8 were measured in bronchoalveolar lavage fluid and plasma by enzyme-linked immunosorbent assay and Western blotting. Eighteen children with acute lung injury were enrolled in the study and compared with eight controls. In children with acute lung injury, there were significant changes in the bronchoalveolar lavage fluid phosphatidylcholine species. Bronchoalveolar lavage fluid dipalmitoyl phosphatidylcholine (PC 16:0/16:0) and palmitoyl-myristoyl phosphatidylcholine (PC 16:0/14:0) significantly deceased during acute lung injury (p < .001 and p < .001, respectively), whereas oleoyl-linoleoyl PC (18:1/18:2), palmitoyl-linoleoyl PC (16:0/18:2) and stearoyl-linoleoyl PC (18:0/18:2) characteristic of plasma PC were significantly increased (p < .05, p < .02, and p < .05 respectively), as well as palmitoyl-oleoyl PC (16:0/18:1), and stearoyl-arachidonoyl PC (18:0/20:4) which are characteristic of cell membranes (p < .02, and p < .02, respectively). There were no significant changes to bronchoalveolar lavage fluid, surfactant protein A or B levels compared with controls during acute lung injury, whereas bronchoalveolar lavage fluid, surfactant protein D, and interleukin-8 levels significantly increased (p < .05 and p < .02, respectively). In plasma during acute lung injury, there were significant increases in surfactant proteins A, B, and D, and interleukin-8 (p < .001, p < .001, p < .05, and p < .001, respectively). Changes to the phosphatidylcholine profile, surfactant proteins, and inflammatory markers of bronchoalveolar lavage fluid and plasma in children with acute lung injury are consistent with an alveolar/blood leakage and inflammatory cell membrane degradation products. These changes are due to alveolar capillary membrane damage and cellular infiltration.

Treatment of endothelium with the chemotherapy agent vincristine affects activated protein C generation to a greater degree in newborn plasma than in adult plasma

Introduction Activated protein C (APC) is well-established as a physiologically important anticoagulant. During development, plasma concentrations of protein C and α 2macroglobulin, factors involved in APC generation, differ from adult levels. Chemotherapy drugs can perturb endothelial expression of PC-activating receptors. This study examines the effect of chemotherapy treatment of endothelium on APC generation in newborn and adult plasma. Materials and methods APC generations were initiated on endothelial cells treated with vincristine or media by recalcifying defibrinated plasma with buffer containing thromboplastin. APC generation was terminated by mixing timed subsamples into FFRCMK-EDTA or heparin, followed by EDTA. APC-PCI and APC-α 1AT were assayed by ELISA. APC-α 2M was measured chromogenically. Since heparin converts free APC to APC-PCI, the difference between APC-PCI detected in heparin subsamples and APC-PCI detected in FFRCMK-EDTA subsamples gave the free APC. Cellular expression of EPCR and TM were measured by flow cytometry and Western blot. Results Vincristine-treated endothelium decreased free APC generation in newborn plasma to a greater degree than in adult plasma. APC-PCI levels in both adult and newborn plasma were unaffected by chemotherapy. Vincristine treatment reduced levels of APC-α 1 AT and APC-α 2 M to a greater degree in newborn plasma versus adult plasma. Expression of EPCR was reduced in cells treated with vincristine. Conversely, TM was reduced on the cell surface, but increased in whole cell lysates. Conclusions The differential response of newborn and adult plasma PC components to chemotherapy-mediated changes in cell surface components may be a factor in the increased risk of thrombosis in children receiving chemotherapy.

The Protective Role of Protein C in Endotoxin-Induced Shock.

The serine protease, activated Protein C (aPC) plays an important role in the maintenance of vascular hemostasis. Besides its ability to regulate coagulation and fibrinolysis, aPC also possesses antiinflammatory and antiapoptotic properties. Severe depletion of plasma PC and aPC contributes to sepsis pathogenesis. Although treatment with recombinant aPC benefits a subset of patients with severe sepsis, mechanisms by which aPC improves survival in these patients remain largely unknown. Using mice genetically predisposed to a severe PC deficiency, we initiated studies to further elucidate the mechanistic relationships between very low endogenous PC levels and inflammatory disease pathogenesis. Here, we show for the first time, that novel genetic dosing of PC strongly correlates with survival outcome following endotoxin (LPS) challenge in mice. Our findings provide evidence that very low endogenous levels of PC predispose mice to early onset of disseminated intravascular coagulation, thrombocytopenia, hypotensive shock, organ damage, and reduced survival after LPS challenge. Furthermore, an excessive inflammatory response is observed in very low-PC mice, but is greatly reduced in WT cohorts. Administration of recombinant human aPC to low-PC mice significantly prevents endotoxin-induced hypotensive shock and prolongs survival. This study highlights the importance of host endogenous levels of PC in predicting survival outcome following a severe acute inflammatory challenge.

COMPARISON OF PLASMA CONCENTRATIONS OF ANTITHROMBIN (AT) AND PROTEIN C (PC) IN BURN AND SMOKE INHALATION INJURY AND SEPSIS

INTRODUCTION Multitraumas are often associated with depletion of endogenous anticoagulants such as PC and AT. The aim of present study was to determine plasma concentration of these anticoagulants in sheep following burn and smoke inhalation and sepsis. METHODS Female sheep (N=20) were operatively prepared to study. Seven days after recovery, tracheostomy was performed under anesthesia. Study groups: Sham (N=5, non-injured, non-treated); BS (N=6), received 3rd degree 40% total body surface area flame burn and insufflation with 48 breaths of cotton smoke; S, (N=5), received insufflation with 48 breaths of cotton smoke followed by instillation of P.aeruginosa into the lungs; treated, [BS or S animals were treated with recombinant human antithrombin (rhAT) and recombinant activated PC (rAPC)]. Plasma AT and PC were assayed using a COAMATIC® kit. Data is reported as mean ± SE. RESULTS AT levels decreased following BS (0h:100±0, 3h:57.3± 5.2, 12h:22.8±4.9, 24h:47.6± 9.4) and sepsis (0h:100±0, 3h:124.8± 8.8, 12h:89±4.2, 24h:44.8± 5.4) as compared to sham animals. PC levels in BS sheep did not differ at all time points (0h:100±0, 3h:101± 5.9, 12h:84.9±8.1, 24h:83.7± 19). PC levels decreased in sepsis animals (0h:100±0, 3h:97.2±14.2, 12h:69.7±10.7, 24h:41.6±8.5). Treatment with rhAT ameliorated cardiopulmonary morbidity in both BS and S. Treatment with rAPC improved cardiopulmonary function in septic sheep, but not in BS sheep. CONCLUSION Restoration of depleted levels of endogenous anticoagulants may be useful in management of multitraumas. Supported by PO12GM066312; R01GM60688; SBI 8450; SBI 8954; SBI 8820

Lipids rich in phosphatidylethanolamine from natural gas‐utilizing bacteria reduce plasma cholesterol and classes of phospholipids: A comparison with soybean oil

We compared the effects of three different high-lipid diets on plasma lipoproteins and phospholipids in mink (Mustela vison). The 18 mink studied were fed one of the three diets during a 25-d period in a parallel group design. The compared diets had 0, 17, and 67% extracted lipids from natural gas-utilizing bacteria (LNGB), which were rich in PE. The group with 0% LNGB was fed a diet for which the lipid content was 100% soybean oil. The total cholesterol, LDL cholesterol, and HDL cholesterol of animals consuming a diet with 67% LNGB (67LNGB-diet), were significantly lowered by 35, 49, and 29%, respectively, and unesterified cholesterol increased by 17% compared with the animals fed a diet of 100% lipids from soybean oil (SB-diet). In addition, the ratio of LDL cholesterol to HDL cholesterol was 27% lower in mink fed the 67LNGB-diet than those fed the SB-diet. When the mink were fed the 67LNGB-diet, plasma PC, total phospholipids, lysoPC, and PI were lowered significantly compared with the mink fed a SB-diet. Plasma total cholesterol was correlated with total phospholipids as well as with PC (R = 0.8, P< 0.001). A significantly higher fecal excretion of unesterified cholesterol, cholesteryl ester, PC, lysoPC, and PE was observed in the 67LNGB-fed mink compared with the SB-fed mink. We conclude that phospholipids from the 67LNGB-diet decreased plasma lipoprotein levels, the LDL/HDL cholesterol ratio, and plasma phospholipid levels, especially lysoPC and PC, compared with the highly unsaturated soybean oil. Our findings indicate that the decrease of plasma cholesterol is mainly caused by a specific mixture of phospholipids containing a high level of PE, and not by the dietary FA composition. The lack of significant differences in the level of plasma PE due to the diets indicates that most of the PE from LNGB has been converted to PC in the liver. Thus, plasma cholesterol may at least be partly regulated by phospholipid methylation from PE to PC in the liver.

Melatonin ameliorates chronic renal failure-induced oxidative organ damage in rats.

Chronic renal failure (CRF) is associated with oxidative stress that promotes production of reactive oxygen species (ROS). Melatonin, the chief secretory product of the pineal gland, was recently found to be a potent free radical scavenger and antioxidant. The aim of this study was to examine the role of melatonin in protecting the aorta, heart, corpus cavernosum, lung, diaphragm, and kidney tissues against oxidative damage in a rat model of CRF, which was induced by five of six nephrectomy. Male Wistar albino rats were randomly assigned to either the CRF group or the sham-operated control group, which had received saline or melatonin (10 mg/kg, i.p.) for 4 wk. CRF was evaluated by serum blood urea nitrogen (BUN) level and creatinine measurements. Aorta and corporeal tissues were used for contractility studies, or stored along with heart, lung, diaphragm, and kidney tissues for the measurement of malondialdehyde (MDA, an index of lipid peroxidation), protein carbonylation (PC, an index for protein oxidation), and glutathione (GSH) levels (a key antioxidant). Plasma MDA, PC, and GSH levels and erythrocytic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were studied to evaluate the changes of antioxidant status in CRF. In the CRF group, the contraction and the relaxation of aorta and corpus cavernosum samples decreased significantly compared with controls (P < 0.05-0.001). Melatonin treatment of the CRF group restored these responses. In the CRF group, there were significant increases in tissue MDA and PC levels in all tissues with marked reductions in GSH levels compared with controls (P < 0.05-0.001). In the plasma, while MDA and PC levels increased, GSH, SOD, CAT, and GSH-Px activities were reduced. Melatonin treatment reversed these effects as well. In this study, the increase in MDA and PC levels and the concomitant decrease in GSH levels of tissues and plasma and also SOD, CAT, GSH-Px activities of plasma demonstrate the role of oxidative mechanisms in CRF-induced tissue damage, and melatonin, via its free radical scavenging and antioxidant properties, ameliorates oxidative organ injury. CRF-induced dysfunction of the aorta and corpus cavernosum of rats was reversed by melatonin treatment. Thus, supplementing CRF patients with adjuvant therapy of melatonin may have some benefit.

The reduced sensitivity of the ProC Global test in protein S deficient subjects reflects a reduction in the associated thrombotic risk.

To investigate simultaneously a defect affecting the protein C/protein S (PC/PS) anticoagulant pathway is possible thanks to a methodological approach (ProC(R) Global; Dade Behring) based on the activation of endogenous plasma PC by a snake venom extract. Factor V (FV) Leiden, the most frequent cause of hereditary thrombosis, is well detected by the test with sensitivity of 100% irrespective of the presence/absence of thrombosis in the subjects investigated. The test is also suited to detect PC or PS defect, but in this case the in vitro impairment of the PC/PS pathway is less pronounced particularly for PS defects (sensitivity for PC and PS defect, 85-100 and 30-90%, respectively). In this study, we hypothesized that the lower sensitivity described for PS defect, compared with those of PC and FV Leiden defects, could also be related to the clinical condition of the subject investigated (symptomatic/asymptomatic) rather than solely to the PS plasma activity/level. Therefore, we analyzed 126 subjects with single congenital defects in the PC/PS pathway: 46 subjects with PS deficiency (26 thrombotic cases and 20 asymptomatic relatives), 40 subjects with PC deficiency (25 thrombotic cases and 15 asymptomatic relatives), and 40 heterozygous FV Leiden subjects (25 thrombotic cases and 15 asymptomatic relatives). By a cut-off of normalized Agkistrodon contortix snake venom ratio of 0.84, the sensitivity in the whole group of cases (sensitivity a) was 76.1, 95.0 and 100%, respectively, for PS, PC and FV Leiden defects. The test failed to detect 11 (23.9%) among the 46 PS-deficient subjects, and all these cases except two belonged to the asymptomatic subgroup (9/20; 45%). Excluding the 20 asymptomatic relatives, the new sensitivity (sensitivity b) for the PS defect was 92.3%. The comparison of the sensitivity in the symptomatic PS cases and in the asymptomatic ones was significantly different (P = 0.010). Among the 40 PC-deficient subjects, only two (5.0%) were not detected by the test and they belonged indifferently to the two subgroups. Finally, none of the 40 FV Leiden heterozygotes were misdiagnosed by the test. These results suggest that in symptomatic PS-deficient cases the test could reflect a post-thrombotic effect and/or reveal potential unidentified prothrombotic influences assessing a prothrombotic risk condition.

An open-label study of the role of adjuvant hemostatic support with protein C replacement therapy in purpura fulminans–associated meningococcemia

Activated protein C (APC) is a natural anticoagulant that plays a pivotal role in coagulation homeostasis. Severe inherited or acquired deficiency results in a clinical syndrome called purpura fulminans. In addition, APC also appears to have potent cytokine-modifying properties and is protective in animal models of sepsis. The dual functional properties of APC are particularly relevant to severe meningococcemia, where acquired PC deficiency is accompanied by multiorgan failure and purpura fulminans. The authors conducted an open-label prospective study assessing the efficacy of PC replacement therapy in patients with severe meningococcal septicemia, purpura fulminans, and multiorgan failure. The morbidity and mortality were compared with predicted morbidity using the Glasgow Meningococcal Septicemia Prognostic Score. Thirty-six patients with a mean age of 12 years (range 3 months to 72 years) were enrolled in the study. The mean ± SD for plasma PC was 18 ± 7 IU/mL. PC was significantly lower than antithrombin or protein S and was also significantly lower than PC levels in a cohort of patients who developed meningococcemia without multiorgan failure and purpura fulminans. A total of 3 of 36 (8%) patients died, which compares favorably with predicted mortality of 18 of 36 (50%). Amputations were required in 4 of 33 (12%) survivors and in 2 of 31 (6.5%) patients who received PC within 24 hours of admission into the hospital, in comparison with the predicted amputation rate of 11 of 33 (30%). In conclusion, PC replacement therapy in severe meningococcal septicemia was associated with a reduction in predicted morbidity and mortality. The beneficial effect of PC replacement may reflect both the anticoagulant and anti-inflammatory properties of the PC pathway.

An open-label study of the role of adjuvant hemostatic support with protein C replacement therapy in purpura fulminans–associated meningococcemia

AbstractActivated protein C (APC) is a natural anticoagulant that plays a pivotal role in coagulation homeostasis. Severe inherited or acquired deficiency results in a clinical syndrome called purpura fulminans. In addition, APC also appears to have potent cytokine-modifying properties and is protective in animal models of sepsis. The dual functional properties of APC are particularly relevant to severe meningococcemia, where acquired PC deficiency is accompanied by multiorgan failure and purpura fulminans. The authors conducted an open-label prospective study assessing the efficacy of PC replacement therapy in patients with severe meningococcal septicemia, purpura fulminans, and multiorgan failure. The morbidity and mortality were compared with predicted morbidity using the Glasgow Meningococcal Septicemia Prognostic Score. Thirty-six patients with a mean age of 12 years (range 3 months to 72 years) were enrolled in the study. The mean ± SD for plasma PC was 18 ± 7 IU/mL. PC was significantly lower than antithrombin or protein S and was also significantly lower than PC levels in a cohort of patients who developed meningococcemia without multiorgan failure and purpura fulminans. A total of 3 of 36 (8%) patients died, which compares favorably with predicted mortality of 18 of 36 (50%). Amputations were required in 4 of 33 (12%) survivors and in 2 of 31 (6.5%) patients who received PC within 24 hours of admission into the hospital, in comparison with the predicted amputation rate of 11 of 33 (30%). In conclusion, PC replacement therapy in severe meningococcal septicemia was associated with a reduction in predicted morbidity and mortality. The beneficial effect of PC replacement may reflect both the anticoagulant and anti-inflammatory properties of the PC pathway.

Role of lecithin-cholesterol acyltransferase in the metabolism of oxidized phospholipids in plasma: studies with platelet-activating factor-acetyl hydrolase-deficient plasma

To determine the relative importance of platelet-activating factor-acetylhydrolase (PAF-AH) and lecithin-cholesterol acyltransferase (LCAT) in the hydrolysis of oxidized phosphatidylcholines (OXPCs) to lyso-phosphatidylcholine (lyso-PC), we studied the formation and metabolism of OXPCs in the plasma of normal and PAF-AH-deficient subjects. Whereas the loss of PC following oxidation was similar in the deficient and normal plasmas, the formation of lyso-PC was significantly lower, and the accumulation of OXPC was higher in the deficient plasma. Isolated LDL from the PAF-AH-deficient subjects was more susceptible to oxidation, and stimulated adhesion molecule synthesis in endothelial cells, more than the normal LDL. Oxidation of 16:0-[1- 14C]-18:2 PC, equilibrated with plasma PC, resulted in the accumulation of labeled short- and long-chain OXPCs, in addition to the labeled aqueous products. The formation of the aqueous products decreased by 80%, and the accumulation of short-chain OXPC increased by 110% in the deficient plasma, compared to the normal plasma, showing that PAF-AH is predominantly involved in the hydrolysis of the truncated OXPCs. Labeled sn-2-acyl group from the long-chain OXPC was not only hydrolyzed to free fatty acid, but was preferentially transferred to diacylglycerol, in both the normal and deficient plasmas. In contrast, the acyl group from unoxidized PC was transferred only to cholesterol, showing that the specificity of LCAT is altered by OXPC. It is concluded that, while PAF-AH carries out the hydrolysis of mainly truncated OXPCs, LCAT hydrolyzes and transesterifies the long-chain OXPCs.

A Modified Functional Global Test to Measure Protein C, Protein S Activities and the Activated Protein C-Resistance Phenotype

Identifying a defect affecting the protein C/protein S (PC/PS) anticoagulant system, using a single global test, has recently become possible thanks to a new methodological approach based on the activation of endogenous plasma PC by Protac®, derived from Agkistrodon Contortix snake venom (ACV). The introduction of a commercial test (ProC®Global), ACV-based, provides a useful tool for the screening of thrombotic patients since the most frequent causes of inherited thrombophilia are found in the PC/PS system. The test provides information only on the global activity of the anticoagulant pathway but not on PC and PS activity or on the factor V related conditions (e.g., FV Leiden). The present study shows that by carrying out the test alternating the presence of PC-, PS-, or FV-deficient plasma and using appropriate amounts of ACV, it is possible to increase the specificity of the test to correctly evaluate respectively the PC or PS activities or the activated protein C resistance condition (APC-R). These simple modifications applied to the original commercial test allow to detect exactly, using a single, basic methodology, the principal defects affecting the PC/PS anticoagulant pathway. Furthermore, carrying out the tests on an automated coagulometer, in combination or not with the classic ProC®Global assay, it is possible to use a unique reagent profile to simultaneously investigate in the same or different samples, the PC, PS, and APC-R defect.